Because of the condition of the head, investigators believe they were dealing with a recent slaying. They identified the head as belonging to a man, possibly of Armenian descent, in his 40s.

Detectives were methodically setting up "grid" searches around where the head was discovered. They also were knocking on doors in the neighborhood, hoping to find potential witnesses.

One resident on Canyon Drive said police were interested in whether body parts might have been dumped in trash cans along the road. If so, the remains would still be present. Trash there is collected on Fridays.

Police believe the body was dumped and the killing probably took place elsewhere.

Photo: An LAPD helicopter searches the area above Bronson Canyon in Griffith Park on Wednesday after a human head was discovered off a hiking trail below the Hollywood sign. Credit: Al Seib / Los Angeles Times